During air-warming operation, a heat exchanger provided to an outdoor unit functions as a refrigerant evaporator. The outdoor air therefore condenses on the surface of the outdoor heat exchanger, and drain water is sometimes formed. Under such conditions, since the outdoor unit of the air conditioning apparatus is sometimes exposed to environments of 0° C. or lower during winter, the drain water sometimes freezes. The surface of the outdoor heat exchanger therefore becomes covered with ice, and the heat exchange performance thereof may decrease.
In contrast, a technique is proposed in the air conditioning apparatus disclosed in Japanese Unexamined Patent Application Publication No. 2008-96018 in which a heater is provided on the top surface of a bottom plate for supporting the outdoor heat exchanger of the outdoor unit, and ice is prevented from forming. Water or drain water which is thawed through the use of the heater is discharged via a water escape hole provided to the bottom plate, and it is therefore possible to suppress the growth of ice on the top surface of the bottom plate.